In this undated photo provided by the St. Louis Symphony is music director David Robertson. The symphony said Tuesday, March 4, 2014 that Robertson has agreed to a contract extension that will keep him in St. Louis through the 2017-2018 concert season. Robertson is also chief conductor and artistic director of the Sydney Symphony Orchestra in Australia, and he is a regular guest conductor at the Boston Symphony, Cleveland Symphony, New York Philharmonic and other orchestras around the world. (AP Photo/Courtesy St. Louis Symphony)